“Additive manufacturing” (AM), also known as 3D free form manufacturing, digital manufacturing, direct metal deposition, shaped metal deposition, etc., refers to a process of joining materials to make three-dimensional (3D) objects as opposed to subtractive manufacturing methodologies, such as machining. 3D printing represents one form of additive manufacturing. Additive manufacturing includes incremental additions of materials in designated locations, often one layer at a time. A “build direction” of the object refers to the direction in which the incremental materials are successively added or stacked. Known apparatuses for additive manufacturing include powder bed systems, powder feed systems, wire feed systems, etc., such as described in Frazier, William E. “Metal additive manufacturing: A review.” Journal of Materials Engineering and Performance 23, no. 6 (2014): 1917-1928, incorporated herein by reference.
Additive manufacturing presents benefits over known processes intended to manufacture complex parts from costly materials, such as metal alloys. Additive manufacturing allows significant reduction in scrap produced using subtractive manufacturing. Instead of machining a part from a work piece of solid material, additive manufacturing uses the amount or nearly the amount of material needed to yield a net-shape or near net-shape part.
Even so, objects produced from additive manufacturing exhibit unique metallurgical and mechanical properties. Although dimensions of an additive manufactured part may be accurately and precisely produced within tolerances, the part may lack the mechanical properties desired given the incremental additions of material. As a result, further additive manufacturing techniques are desired that enhance metallurgical and/or mechanical properties.